Isooctenyl 2, 4-dichlorophenoxyacetate



Oct. 17, 1961 D. w. YOUNG ISOOCTENYI.. 2 4DICIILOROPHENOXYACETATE Filed June l, 1959 R. m. 35..; im or 23:55 2.5-@ WW. .35.21 $6.0 um $8. Q Im. w wzomz z 152m.. n; Q N- 9 m h w m e m N W D D 51H4 a ON D T e s2 m 4 s; 2 N E W @.Lf /Qw i. 75C il om f. l @t\\f\l\ i/(Mwp Nolssmsuvw. Navasa ATTORNEYS United States Patent C) f ISOOCTENYL 2,4-DICHLOROPHENOXYACETATI11 David W. Young, Homewood, lll., assiguor to Sinclair Refining Company, NewYork, N.Y., a corporation of Maine Filed June 1,1959, Ser. No. 817,380 1 Claim. (Cl. 260-473) My invention relates to a novel composition of matter, the ester of isooctenyl alcohol and 2,4-dichlorophenoxy acetic acid, and its use as a herbicide.

Esters of 2,4-dichlorophenoxyacetic acid (2,4-D) are known to have value as herbicidal agents for Weed and brush control. 'Ihe common esters (ethyl, propyl, and butyl) have a high potency, but their use is accompanied by a severe drawback, their tendency to drift. t

Drifting is a phenomenon which is associated with volatility and, in the case of Weed killers, is `the tendency of a composition to wander from Ithe plot of ground to which it is applied'over to neighboring elds. Certain crops, notably cotton, are extremely susceptible to..2,4 dichlorophenoxyacetic acid and its derivatives, and can be severely damaged by vapors of the Weed killer which may drift from fields which are planted with crops tolerant to the weed killer, such as rice. Because of the high volatility of most of the available esteried forms of 2,4-D, the residual activityof the herbicide suffers, and Weed control is no t a's long lasting as lWould be desirable.

I have found that the novel ester of isooctenyl alcohol and 2,4-dichlorophenoxyacetic acid possesses good herbicidal activity and is of the low volatile, no drift type. Surprisingly, the ester is less toxic in vapor drift than similar esters of the low volatile type, e.g. saturated branched chain alcohol esters of the same -number of carbon atoms. The novel ester possesses all the desirable characteristics of a useful herbicide. VIt is of low volatility, -forms emulsifable concentrates, -is soluble in low cost aromatic solvents, is highly selective in herbicidal activity and has good herbicidal activity.

The isooctenyl alcohol useful in preparing the esters of my invention can berepresented by the general f'formula (CH3)3CROH wherein R is branched alkenyl of 4 carbon atoms, e.g.Y

CH3 CH3 CHT-c-CH=o- H1OH (IDH: (II) and (I'JH: ICIH; CHs-fIl-CHr-C-CHzOH CH3 (HI) The isooctenyl alcohol used can-comprise a mixture of alcohols such as those ofV Formulas 1I and III.

The isooctenyl alcohol can be conveniently prepared by the hydrolysis of the corresponding chloride which in turn can be prepared by chlorinating diisobutylene. Isooctenyl chlorides can be prepared, Jfor example, `by the liquid phase chlorination of diisobutylene with chlorine, e.g. at about 90 to 110 C., with removal of evolved hydrogen chloride, as described in U.S. Patent 2,783,285 to Chambers and Foster or by the vapor phase chlorination of diisobutylene with chlorine, e.g. at about 100 to 200 C., using a substantial stoichiometric excess of diisobutylene as described in U.S. Patent 2,785,207 to Chambers and Foster. Such isooctenyl chlorine can lbe hydrolyzed to isooctenyl alcohol, for example, by hydrolysis in aquey 3,005,016 I .y Patented Oct. 17, 1961 ICC 21. ous alkaline medium, eig. at about C. to car-bonization temperature, as described in: pending. applications S.N. 347,222, iledA April 7, 1953 and S.N. 412,633, led February 25, 1954, of Chambers and Foster. v

The novel ester can be prepared by conventional esterication techniques. Advantageously, the esteriication is carried out by dissolving 2,4-dichlor'ophenoxyacetic acid in an inert organicsolvent, eg'.V` toluene, adding the isooctenyl alcohol to .the solution, heating the mixture in the presence, of an esterication catalyst and recovering the ester. Zinc 'stearate is'the preferred catalyst.Y Catalysts such as p-toluene sulfonic acid and titantium tetrachloride are not-useful in the esteriiication as they add to the double bond of the alcohol and produce side polymerization.

The novel ester is a liquid and canbe used as a herbicide in the same manner as the knownY esters of 2,4-D and at the same concentrations as 2,4-D and its known esters. For use as a herbicide, the ester can be formulatedrwith conventional Vherbicidal carriers. Advantageously, the ester is usedasa spray. As sprays, the ester canbe formulatedy as concentrates in conventionally used oils, Velg.l a horticultural spray oil such as a parafiinic white voil of 40G-600 F. boiling range, diesel oil, or kerosene, and liquid? aromatic solvents,- e.g. xylene or methyl naphthalenes, and applied as such or as emulsions in water. In. such concentrates, the amount of the ester can vary Widely but generally is about l0 to 30%, preferably about 15 %,-and the resulting solution can be diluted with Water for use, for example,vat about4 l fluid ounce per gallon of water. Also, theester can be emulsied in water and .sprayed as such.` In the solutions or emulsions, conventional agents canvfb'e employed -to insure good emulsicationand good contact with the foliage of treated vegetation.V Typical satisfactory conventional agents for wetting, dispersionY and emulsi-cation y include the alkylaryl` sulfonates, the fatty alcohol sulfates, sodium salts of naphthalenesulfonic acid, long chain qua- ,ternary ammonium, "compounds and sodium salts of petroleum-derivedalkylsulfonic acids. The herbicidal compositions containing the ester areefective and can be used -in concentrations of ffromfabout 2 to 150 pounds per 100 gallons of finished spray per acre.

The novel ester can also be used as a dust by impregnation on a solid carrier,- e.g. lime, talc,.bentonite, pyrophyllite and calcium carbonate. The finely-divided solid containing the ester, e.g. -in a concentration of about 10 to 30 weight percent, is then applied to the vegetation. Also, the ester cangbe impregnated on.:a clay, e.g. in a concentration of about 10 to 30 weight percent, and

formed into pellets andY utilized in this form to destroy or control algae and aquatic Weeds, e.g. lilies, cattails,

Aalligator -Weedselodea, milfoil, Vfanwart,I tape grass and .ludwigia by` dropping the pellets into the water containing therweeds. Also, the ester can lbe incorporated into .grease-like formulations to permit brushing or daubing ofthe herbicidal esteronto-specic weeds or plants. The

'grease-like formulations can be obtained by dispersing e.g. dandelion, plantains, poison ivy, poison oak, rag- Weed, docks, chickweed, -thistles and mustards.

My invention will be further illustrated by `the following examples.

, Y3, i .Y A

o 1 Y p Y Preparation of soqctenyl ester of 2,4-v `dcrtlomphefzfmcyac'etc acid A gA-diehierophenoxyacetie.acid (v 1, Vruote) 'was added toV 250 of toluene in a tlaslc.` To this'was added 1.05 moles of isooctenyl alcohol, To this r'niXture was added the root elongation determined at the end of this time.

' The results are recorded in table form-below:

0.5% zinc stearate (calculated on Weight of acetic ester'y V'ClGH'Z'ggClZ, Vcalcd:r C,Vr58'.00;A'I, 6.65; Cl, 21.4. Fouad: C, 58.38; H,16.1s;,c`17,V 20.8.'V d 4 Y Y The rinfrared spectra offthe isooctenyl ester `of 2,4-dehlorophenoxyacetic acid .product (as determined with a model Zl-Perkins-,Elmer infrared spectrometer) are illustrated in the accompanying drawing :whichris a reproduction of the infrared curves obtained with k(1) ,a 100% sample (liquid) `in :110.07247mm. cell and' (V2) a (lilm (liquid)V between twosalt plates.

'treated Was 100 sq. vft. in each study.

Ester: Average root length, mm.

Y isopropyl 2,4-D Decyl 2,4-D V 'Y Y 26 lsooctyl Y2,4D 28 But'oxyethyl 2,4D 3l Tridecyl 2,4-D e 38 Control l f l 52 Isooctenyl 2,4-D 37 These data show that the nisooctenyl alcohol 2,4D ester has lower vapor-toxicity than most of the other lowvolatile esters and in particular have less vapor toxicity at the same carbon number than the saturated chain alcohol ester, i.e. the -isooctylY alcohol ester.

EXAMPLE 3 ln this study the rateY of application was constant at a concentration of 4 ounces per gallon. 'The amount of ester-water solution or emulsion used was the amount to wet the weed or woody plant in agrass plot. The percent of weed `kill is indicated in the table. The area The spectrum of the sample of the isooctenyl ester of 2,4-dichlorophenoxyacetic acid `'was analyzedv employing Y the acceptedcorrelations for infrared 4absorption band position and chemical structure., yThe spectrum clearly shows the presence oft-an .esterfgrop .This yis indicated byV .the carbonyl band at 5.8 microns and the Vcarbonoxygen stretching vibrationgat 8.4 microns. The carboncarbon double bond ofthe ilsooctenyl group is observed as a strong sharpA absorption band at'6.06 microns.V The band at 6.3 Vmicrons is characteristic of ,aromatica The 7.1-7.4 micron region of Athe'.spectrum indicates'lthe presence of ltwo methyl groups on a kcommon tertiary carbon 'located Vin theisooctenylgrenp. Y v

The absorption bandsfinthe long wave lengthrregion of lthe spectrum (11%15' microns) clearlyY indicate the presencelof l,2,4'trisubstiti1ted armatics. The bands in enceY Vsprecritrum of 2,;4jdichlorophenoxyacetic acid (Sadtler standard spectra #1583CA) asv would beV expected. The

Vabsorptio'n band at 13.08 microns is probably due to an vapor-'tertiary of' variedsf-herbeidal esfersef 2,4-D

was determined. Pregerininated cucumber seeds, Aa sus- The above results show that the isooctenyl 2,4-D ester effectively kills weeds in a grass plot. VObservation on flowers, etc. show less vapor toxic drift kill or' blight for icooctenyl 2,4-D than for butoxyet-hyl 2,4-D.

EXAMPLE 4,

- A'herbicidal concentrate -is prepared by dissolving v1.4

Y parts by weight of isooctenyl ester of 2,4-D in 86 parts Ythis region are comparable with'tliose toundra a referceptiblecrop, were used Vastest specimens'. The seeds n i were sealed ijnv polyethylene bags containingfsucient moisture for normal growth and a predetermined quantity (3.36 g.) o f theester on tilter paper. The test specimens were maintained atr to, 80 F. for 72`hou'r's and ,by Weight of kerosene.

Vas a spray at l water.

The concentrate can be sprayed as such on Weedsl or plants or diluted Wirthwater for use uid'ounce of concentraterper'gallon of emulsiiia-ble concentrate suitable for use when di- A composition suitable for use as a dust is composed of finely-divided bentonite on which has been impregnated 14 percent by weight of isooctenyl ester ofV2,4-D.

I claim: t,

Isooctenyl -alcohol ester of 2,4-diehlorophenoxyacetic acid.

References YCited in thefile of this patent UNITED STATES PATENTS 

